The present invention relates to a cooling controller for cooling an internal-combustion engine such as an internal-combustion engine for an automobile, and particularly to a cooling controller for an internal-combustion engine that can prevent an internal-combustion engine from overheating in the case where the thermostat or other parts may fail.
In an internal-combustion engine (hereinafter abbreviated as xe2x80x9cenginexe2x80x9d) for use in an automobile, a water-cooled type cooling device using a heat exchanger (hereinafter referred to as xe2x80x9cradiatorxe2x80x9d) for cooling the engine has been utilized. In such a cooling device, a thermostat is utilized as a cooling control means to control the temperature of the cooling water. If the temperature of the cooling water is lower than a designated temperature, the thermostat is closed so the cooling water circulates within a bypass route, not through the radiator. If the cooling water becomes higher than a designated temperature, the thermostat is opened and the cooling water circulates within the radiator.
The conventional cooling controller for an internal-combustion engine is shown in FIG. 7. In the cooling controller 100 for an internal-combustion engine in this figure, a fluid passage shown by the arrow is formed within an engine E composed of a cylinder head 101a and a cylinder block 101b. Further, a cooling water channel 102 for circulating the cooling water is placed between the engine E and radiator R.
The cooling water channel 102 is composed of a cooling water channel 102a connecting an outlet for the cooling water provided at an upper portion of the engine E with an inlet of the radiator R, a cooling water channel 102b provided from an outlet of the radiator R to an inlet for the cooling water provided at a lower portion of the engine E, and a bypass channel 103 which connects the cooling water channel 102a at the outlet side to the cooling water channel 102b at the inlet side. A thermostat 104 is placed on a branch portion between the cooling water channel 102a at the outlet side and the bypass channel 103. The thermostat 104 embeds a heat responding element, which expands or shrinks due to changes in the heat, like a wax does. When the temperature of the cooling water is high, the valve is opened by the expansion of the heat responding element to allow the cooling water flowing from the engine E to enter into the radiator R via the cooling water channel 102a at the side of the outlet, and the cooling water having a low temperature due to the heat radiation by the radiator R passes through the bypass channel 103 to flow into the cooling channel within the engine E from the inlet of the engine E.
When the temperature of the cooling water is low, the valve of the thermostat 104 is closed due to the shrinkage of the heat responding element, and the cooling water flowing from the outlet of engine E passes through the bypass channel 103 to enter from the inlet of the engine E into the cooling channel within the engine E.
A water pump WP is placed at the inlet of the engine E, and by the rotation of a crankshaft (not shown) of the engine E, the rotation shaft of the pump is rotated, forcing the cooling water to be circulated. In addition, the radiator R is provided with a cooling fan 105 for forcible intake of the cooling air, and is composed of a cooling fan 105 and a fan motor 106 for rotating the cooling fan 105.
The conventional cooling device described above has the following problems: when the fan motor 106 of the cooling fan 105 in the radiator R has a problem, or any problem occurs in the thermostat 104 such as the valve being left closed so the cooling water does not circulate into the radiator R, the cooling water is not cooled. Consequently, the engine E attains a state of overheating.
A cooling controller for an internal-combustion engine according to the present invention has been made in light of the above situation, and provides a system which can prevent problems such as overheating, even if the radiator or the thermostat has failed and which can exhibit fail-safe functions.
A cooling controller for a internal-combustion engine according to the present invention which solves the problems described above, includes:
a first heat exchanger configured by forming a circulation channel for a cooling medium between an internal-combustion engine and a heat exchanger to radiate out heat generated in the internal-combustion engine through circulation of the cooling medium, and a second heat exchanger which radiates out heat by forming a second circulation channel for air conditioning an automobile cabin, the cooling controller further comprising:
a temperature detecting means to detect the temperature of said cooling medium, wherein the temperature detecting means is placed in at least one of said first or second circulation channels,
a flow amount control means to control the flow amount of said cooling medium,
a driving condition detecting means for said internal-combustion engine,
an internal-combustion engine control means to control said internal-combustion engine based on the output signal from said driving condition detecting means,
an air conditioner for air conditioning the automobile cabin utilizing the heat radiation of said second heat exchanging system,
an air conditioner control means to control said air conditioner, and
said air conditioner control means outputting an operating signal which maximizes an amount of heat radiated from said second heat exchanger for air conditioning when an abnormality of the cooling function of said internal-combustion engine is detected by said input signal from said internal-combustion engine control means.
A cooling controller having such a configuration can allow the cooling medium to cool down through the second heat exchanger, even if said first heat exchanger or said flow amount control means is defective and does not allow the cooling medium to cool down, making it possible to take precautions against serious problems such as overheating.
Furthermore, said flow amount control means is preferably characterized by opening or closing the thermostat valve through an input signal from said internal-combustion engine control means.
The flow amount control means can carefully control the angle of the valve and, thus, the flow amount in said first circulation channel can be controlled with high reliability.
The present invention also relates to a cooling controller for an internal-combustion engine comprising:
a first heat exchanger configured by forming a circulation channel for a cooling medium between an internal-combustion engine and a heat exchanger to radiate out heat generated in the internal-combustion engine through circulation of the cooling medium, and a second heat exchanger which radiates out heat by forming a second circulation channel for air-conditioning an automobile cabin, which cooling controller further comprises:
a temperature detecting means to detect the temperature of said cooling medium, wherein the temperature detecting means is placed in at least one of said first or second circulation channels,
a flow amount control means to control the flow of said cooling medium,
an air conditioner for air conditioning the automobile cabin having said second heat exchanger and carrying out air conditioning utilizing the cooling medium of said internal-combustion engine,
an air conditioner control means to control said air conditioner, and
said air conditioner control means outputting an operating signal which maximizes an amount of heat radiated out from said second heat exchanger when the input signal from said temperature detecting means is higher than a designated temperature.
The flow amount control means is preferably a thermostat which opens or closes a valve by means of a thermal expansion means embedded in a casing.
A cooling controller for an internal-combustion engine having such a configuration has a relatively simple configuration, and can automatically open or close the circulation channel of said cooling medium.